The present application relates to non-aqueous electrolytic solution that is used in a secondary battery, to a secondary battery that uses the non-aqueous electrolytic solution, and to a battery pack, an electric vehicle, an electric power storage system, an electric power tool, and an electronic apparatus that use the secondary battery.
In recent years, various electronic apparatuses such as a mobile phone and a mobile information terminal device (PDA) have been widely used, and it has been demanded to further reduce the size and the weight of the electronic apparatuses and to achieve their longer lives. Accordingly, as an electric power source, a battery, in particular, a small and light-weight secondary battery capable of achieving high energy density has been developed.
In these days, it has been considered to apply a secondary battery to various other applications in addition to the electronic apparatuses described above. Examples of such applications other than the electronic apparatuses may include a battery pack attachably and detachably mounted on the electronic apparatuses or the like, an electric vehicle such as an electric automobile, an electric power storage system such as a home electric power server, and an electric power tool such as an electric drill.
There have been proposed secondary batteries that utilize various charge and discharge principles in order to obtain battery capacity. In particular, attention has been paid to a secondary battery that utilizes insertion and extraction or precipitation and dissolution of an electrode reactant, because higher energy density is achieved in such secondary batteries than in a lead battery, a nickel-cadmium battery, etc.
A secondary battery includes a cathode, an anode, and non-aqueous electrolytic solution. The cathode includes a cathode active material related to charge and discharge reactions, and the anode includes an anode active material related to charge and discharge reactions. The non-aqueous electrolytic solution includes a non-aqueous solvent and an electrolyte salt. A composition of the non-aqueous electrolytic solution largely influences battery characteristics of the secondary battery. Various considerations are therefore made on the composition of the non-aqueous electrolytic solution.
Specifically, in order to achieve higher battery capacity, etc. a compound including boron (B) as a constituent element is contained in the non-aqueous electrolytic solution (for example, see Japanese Unexamined Patent Application Publication No. 2013-131394, and Japanese Patent Nos. 5013776 and 4610490).